1. Field of the Invention
The present invention relates to pass-through information transfers inserted after a continued primitive in serial communications between a device and a host. More particularly, the present invention relates to serial communication in accordance with a Serial Advanced Technology Attachment (SATA) format in which pass-through information may be inserted into information transfers that is recognized by enabled devices and ignored by non-enabled devices.
2. Description of the Preferred Embodiments and Related Information
Today, computing devices, such as computers, are routinely used both at work and in the home. Computing devices advantageously enable file sharing, the creation of electronic documents, the use of application specific software, and access to information and electronic commerce through the Internet and other computer networks.
Typically, a host computer is connected to another device, such as a storage peripheral (e.g. a hard disk drive). Storage devices and other types of devices are typically connected to a host computer through a host interface connector for the transfer of commands, status and data. For example, a host computer may access a disk drive device and read data from the disk drive and/or save data to the disk drive.
The host computer is typically connected to a device, such as a disk drive, through a cable connection or a printed circuit board (PCB) connection. This connection is generally termed an “interconnect”. For compatibility, the connectors, cables, and interface protocol are typically standardized. Accordingly, the interfaces of both the device and the host need to comply with the same interface standard.
In the past, a host computer was typically connected to an external storage device, such as a hard disk drive, by a parallel interface. The most common parallel interface is the Parallel Advanced Technology Attachment/Integrated Drive Electronics (PATA/IDE) interface.
Today, storage devices, host computers, and other devices, are being designed to comply with newer faster standards that operate in a serial fashion. Examples of these newer serial standards include the Serial Advanced Technology Attachment (SATA) standard and the Serial Attached SCSI (SAS) standard. Both the SATA and SAS standards define various related specifications for SATA and SAS compliant connectors and cables, along with various interface protocols for SATA and SAS devices, respectively.
The serial interface defined by the related SATA and the SAS protocols relates to the transfer of commands, data, and status via frame information structures (FISs). Unfortunately, the related SATA and SAS protocols do not allow for extensions to the protocol to provide enhancements without introducing significant compatibility issues with prior devices.